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By Martin S. Oudenhoven

This Bureau of Mines report presents the results of a microseismic study conducted in the Climax block cave mine at Climax, Colo. Rock noises created by caving were monitored and their sources located during a 3-month period. A planar array of seven accelerometers, located above the block of ore being caved, detected the rock noise. A computer was used to calculate the location of the microseismic activity, using a traveltime difference method. The accuracy of these locations was estimated to be ±20 feet. An analysis of the data taken during the recording period showed a concentration of microseismic events located in the wall of the cave panel. This concentration of events was found to occur in a "high-silica" geologic forma-tion that cut across the caving panel approximately 200 feet behind the undercut.

Jan 1, 1973

By A. J. Forney

A high-Btu gas was made at the Bruceton, Pa., laboratories of the Bureau of Mines to demonstrate the feasibility of using the gas as a nonpolluting fuel for automobiles. The pilot plants at Bruceton were revised to combine the processes of coal gasification, gas purification, and catalytic methanation in one overall system. Tests in the Bureau's test automobiles at Bartlesville, Okla., showed the Synthane gas was less polluting than natural gas.

Jan 1, 1972

By L. Cheng

This report describes a laboratory investigation of the effectiveness of low-pressure steam and a steam-water spray sequence for the collection of airborne respirable (<10 µm) coal dust. Comparison of present results to previous results obtained with water spray alone indicates that the use of steam in a steam-spray sequence increases the collection efficiency by about 14 percent over that obtained by water spray alone. However, the use of steam to collect airborne dust requires cooling the steam-dust mixture in order to achieve condensation of the steam, and steam does not appear to be an attractive approach for collecting airborne dust in underground coal mining operations.

Jan 1, 1974

By Edward D. Thimons

As U.S. mines go to greater depths, the high temperatures and humidities characteristic of such depths make it difficult to maintain a comfortable environment in working areas. Better techniques for cooling these deep working areas are needed. At the Homestake gold mine in South Dakota the Bureau of Mines has tested a water spray cooler inserted into the fresh air vent tube entering a warm stope. The cooler supplied more than 6 tons of refrigeration to the stope air, which dropped from an inlet temperature of 83° F dry bulb and 75° F wet bulb to 73.5° F dry bulb and 71.5° F wet bulb. These preliminary results show the water spray cooler to be a feasible concept. However, there is a need for substantial refinement and further testing, and work on the concept will be continued under contract to the Bureau.

Jan 1, 1979

By R. H. Nielsen

A new, cheaper precipitation scheme has been developed to produce purified zirconium oxide, Technical-grade sulfuric acid is used to precipitate a basic zirconium sulfate from a hot dilute hydrochloric acid solution. With close control of temperature, pH, and zirconium - sulfate ratio, excellent purification and complete zirconium recovery can be attained. The process has been successfully applied for 3 months and has proved to be a more satisfactory procedure than the ammonium phthalate process used previously. INTRODUCTION The Northwest Electrodevelopment Laboratory of the Federal Bureau of Mines has developed and improved the Kroll process for the production of pure ductile zirconium and hafnium. metal. Since 1946 over 1 million pounds of zirconium sponge metal has been produced, mostly high-purity material for the Atomic Energy Commission

Jan 1, 1956

By E. D. Eastman

There are three researches upon the specific heat of water vapor by the method of explosion that are sufficiently advanced in technique and suitable in plan to justify careful study of their results , with the double purpose of fixing the best available experimental values and indicating the attainable accuracy of the method. These three researches comprise the work of Pier , Bjerrum , and Siegel.5 The work of earlier date than Pier's suffers from obvious inaccuracy of measurement , while the experiments more recent than Siegel's , such as those of Womersley6 , of Bone and his collaborators , and of Maxwell and Wheeler , 8 are for the most part not well designed for the accurate determination of the heat capacities in question . Some of the errors to which they are especially subject have been discussed by David and by David and Thorp.

Sep 1, 1930

By C. J. Thompson

Two sulfur compounds--the 2,2,5-trimethyl- and the 2,2,5,5-tetramethyl derivatives of thiacyclopentane--were identified in Wilmington, Calif., crude oil, using microdesulfurization and gas-liquid chromtography techniques.

Jan 1, 1963

By R. V. Ramani, R. A. Jankowski, R. Bhaskar

"The spatial distribution of airborne dusts, deposition of dust in the airway, as well as the effect of airflow velocity and particle density on dust behavior in mine airways were studied in a set of experiments performed in a mine airway under controlled conditions. Considerable deposition of dust near the source was indicated. Pronounced effects due to velocity were observed in ambient dust concentration and deposition along the mine airway, both in the respirable and the total size ranges. Cross-sectional concentration measurements indicate an increase in concentration from the roof to the floor. The average cross-sectional concentration is about 75% of the concentration in the center of the airway.IntroductionA number of studies have been performed since the early 1950s on the behavior of dust in mine air (Bradshaw and Godbert, 1954; Dawes and Slack, 1954; Bradshaw et al., 1954; Hall, 1955-56; Reinhardt, 1971; Ford, 1971; Courtney et al., 1982). While the experimental data available from these studies are indeed useful in understanding dust cloud behavior in a specific situation, no generalized conclusions can be drawn because of the lack of data on parameters such as flow velocity, size distribution of the source dust, and particle density. These change from mine to mine or even within the same mine. The present study is aimed at providing a better understanding of the temporal and spatial behavior of dust particles in underground' mine airways (National Academy of Sciences, 1980). The characteristics studied encompassed airborne concentrations and floor depositions over the entire size range as well as the respirable size range. The experimental results in this paper are intended to complement a mathematical model developed to predict ambient concentration and deposition of airborne dust in mine airways (Bhaskar and Ramani, 1986)."

Aug 31, 1989

By M. A. Mahtab

This report presents the geometric parameters (attitude, spacing, extent, and aperture) of fracture patterns in a selected portion (study area) of San Manuel copper mine, Arizona. The geometric parameters are quantified for input to structural analyses for studies of the influence of fractures on cavability of ores. Using an orientation analysis procedure developed earlier by the Bureau, three prominent and nearly orthogonal sets of fracture orientations were delineated in the study area. Sets 1 and 2 dip nearly vertically, and generally strike east-west and north-south, respectively, whereas set 3 is nearly horizontal. Both a horizontal rotation (of 14° to 26° for sets 1 and 2, respectively) and a tilt (of 20° for set 3) is shown to occur between the 1415 and 2015 levels of the mine. Gomparison of the three major rock types present in the study area (quartz monzonite, monzonite porphyry, and rhyolite) show that the rhyolite is characterized by short extent, small spacing, and tightness of fractures as well as the general absence of fracture set 3, which may account for its generally observed strong resistance to caving.

Jan 1, 1973

By H. B. Brunot

On April 26, 1949, the Bureau first approved a machine designed to replace the cycle of cutting, blasting, and loading coal by a single operation. This machine took the coal directly from the solid face and delivered it to transportation equipment. By January 1, 1955, 30 approvals for designs of machines of this type had been granted by the Bureau. In the main, this paper describes briefly the action of the various designs approved as permissible. In addition, the approval number, the date of approval, the voltage of the power supply, the number and character of the explosion-proof accessory parts, the size of the trailing cable, and the overcurrent protection at the outby end of the trailing cable are given for each design. Since no similar information has been published by the Bureau, it is hoped the material in this paper will be valuable in giving the mining public an organized look at the various machines of this nature that have been approved as permissible by the Bureau.

Jan 1, 1956

By Victor E. Kral

"SUMMARYA preliminary examination of the Buena Vista iron deposit was made in June 1942 by Paul E. Pesonen, mining engineer of the Bureau of Mines. Subsequent examinations were made by D. W. Butner, of the Bureau, in March 1943, and by the author in July 1944, who recommended exploration by diamond drilling, trenching, and sampling. Work on the project was done during the period March 28 to May 26, 1945.Property holdings, comprising 16 claims known as the Buena Vista group, are situated in sec. 4, T. 24 N., R. 34 E., Mount Diablo base and meridian, north Churchill County, about 37 miles east of Lovelock, Nev.Three diamond-drill holes totaling 575 feet were drilled; 45 small pits and ten trenches, totaling 435 linear feet, were excavated, and 84 channel samples totaling 862 feet were obtained under supervision of the Bureau.Purpose of the project was to determine the possible downward extension of the mineralized sections exposed in the outcrops and to determine grade of the ore.Bureau work was confined to one claim only - the Iron Mountain."

Jun 1, 1947

By Robert D. O'Brien

"INTRODUCTION The Miscellaneous Minerals Division of the War Production Board requested the Bureau of Mines to investigate the Gallatin corundum property as a possible source of corundum, which was in short supply due to the war. The Gallatin corundum property, also known as the ""Fuller mine"", the ""Montana Corundum mine"", and as the ""Old Qorundum mine"" was first examined by a Bureau of Mines engineer 2/ in July 1943. Bureau of Mines work on the property started October 11, 1943, was recessed May 5, 1944, and was resumed in October 1944 when the diamond-drilling program started. The project was completed February 7, 1945. The data obtained are given in this report.The Federal Geological Survey made a reconnaissance survey in the spring of 1943 and mapped the area the following autumn. The results of these surveys are contained in a memorandum report prepared in December 1943.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests."

Aug 1, 1947

By Roy L. Wilfong, LeRoy R. Furlong, Louis P. Domingues

The bulk and apparent densities , particle size , and surface area of ceria powders derived from the ammonium sulfate , carbonate , nitrate , oxalate , and sulfate salts and heated at 950 ° to 1,500 ° C for 1 to 24 hours were studied . The bulk and apparent densities and particle size generally increased , and surface area decreased with increase in temperature and time of heating ; surface area was more sensitive to changes in temperature and time than the other properties studied . These properties of the ceria powders had a marked dependence on temperature and a lesser dependence on duration of heating at a given temperature ; and the source of oxide and thermal treatment cannot be considered optional in the preparation of refractory powders by thermal decomposition . The ammonium sulfate and sulfate salts heated at 950 ° and 1,200 ° C produced oxide powders with the lowest bulk density , the smallest particle size , and the highest surface area . The highest apparent densities were achieved for oxides resulting from the carbonate and the sulfate but the carbonate - derived material was considerably coarser . The surface areas of ceria powders derived from cerium salts decrease in the order of sulfate , ammonium sulfate , nitrate , oxalate , and carbonate . The observation of these physical properties are useful in predicting the sintering behavior of various oxide powders .

Jan 1, 1964

By Charles Vaught, Richard S. Fowkes, Ronald S. Conti, Barbara Fotta, William J. Wiehagen

The purpose of this study was to determine mine workers&apos; state of fire-fighting preparedness and the technology being used to detect and respond to underground coal mine fires. To investigate this problem, 214 underground coal miners were interviewed by U.S. Bureau of Mines researchers. Frequency distributions of workers &apos; responses are presented in this report, along with segments of narrative accounts, to profile miners&apos; fire-fighting capabilities. The data indicated that much variability exists from mine to mine and that there are several important changes operators may undertake in order to make miners better prepared to deal with fire underground: select appropriate sensors, establish and test a warning and communication protocol, construct a system capable of delivering hundreds of gallons of water per minute for sustained periods, institute formal fire preparedness audits, develop case studies of events that occur at an operation to use as teaching and assessment tools, and provide structured practice that can be incorporated into fire drills.

Jan 1, 1995

By R. W. Holliday

To determine the copper and nickel content of reported ore occurrences in the Chippewa mine near Rockmont, Douglas County, Wis., the Bureau of Mines reopened and sampled the old shaft and workings during the summer and fall of 1953. Occurrences of native copper near Rockmont and others near Gordon, also in Douglas County, Wis., are in lava flows, which extend from the Keweenaw Peninsula of Upper Michigan southwest across Wisconsin and into Minnesota. Sporadic attempts have been made to find additional economic copper deposits in these flows since profitable mines were developed in Upper Michigan nearly 100 years ago. The Rockmont and Gordon areas were explored extensively more than 50 years ago. More recently, from August 1944 to duly 1945, an occurrence near Gordon was investigated by the Bureau.2/

Jan 1, 1955

By R. Hogg, S. Chander

"The distribution of the wettability of coals of different rank was determined by measurements of contact angles for individual particles. The contact angle was estimated from the equilibrium partitioning of a particle at the water/air interface. Using this technique contact angles were determined for a larger number of particles from a given sample and a frequency distribution of contact angle was obtained. The contact angle distribution was broad for all the coals tested with included an anthracite, a hvA bituminous and a sub-bituminous coal. In comparison, spherical particles of polymethylmethacrylaie gave a much narrower distribution. The distribution for irregular polyethylene particles was somewhat broader than that for the polymethylmethacrylate spheres but broader than that for the polymethylmethacrylate spheres but considerably narrower than that for coal. The broader wetting distribution for coal was attributed to differences in surface chemical properties.INTRODUCTIONA knowledge of the wetting properties of coals is very useful in coal cleaning by flotation and other processes in which separations are based on differential surface properties. The various methods available for measuring wetting characteristics include: contact angle, 1-2 time, time, 3-5 bubble attachment, 6 film flotation,7 displacement pressure, 8-9 penetration rate, 10-11 bubble pick-up, 12 induction time, 13 imbibition time, 14 and calorimetry. 15-16 Of all these methods, however, the measure¬ment of contact angle by the sessile drop and captive bubble techniques have been most widely used. Brady and Gauger"" demonstrated through the use of the contact angle method that the natural hydrophobicity of coal varied greatly from sample to sample. Subsequent experiments showed that this difference correlated well with rank, the larger contact angles generally being associated with the higher rank coals. 18-19 More recent studies by Aplan and co-workers' show that the wettability of various ranks of coals as determined by sessile drop and captive bubble methods is a more complex function of rank. The hydrophobicity of coal usually increases with rank up to about 80% fixed carbon (dmmf) and then decreases."

Mar 1, 1992

Reduce the potential of haulage related injuries in underground mines by providing a method for quickly assessing the state of repair of mine haulage track. The Problem Currently, there are no established standards or procedures for inspection or cleaning of underground mine haulage track. Many track defects are hidden from an inspector because of layers of dirt and debris on the ballast, spikes, fishplates, etc. When a visual inspection can be performed, it may be highly subjective, except for a few items that can be categorized or counted, such as missing bolts or spikes. Track inspectors may even become tolerant of defects that can gradually worsen. For these reasons, mechanical inspection methods are needed to supplement visual inspections. Approach The Bureau investigated this problem and designed a towed vehicle to both mechanically clean and inspect underground coal mine haulage track. The vehicle was developed using a systems approach, paying particular attention to human factors issues such as operator field of view, operator ingress-egress, control positioning, and seating design. The prototype was built using simple fabrication techniques and off-the-shelf components.

Jan 1, 1990

By S. R. Borrowman

Mill tailings from conventional uranium extraction processes contain nearly all of the radium originally in the ore. Such tailings require controlled storage in perpetuity to safeguard the surrounding environment from radioactive contamination. Alternatives to controlled storage of the tailings are (1) removal of the radium from the tailings for separate storage or use or (2) removal of the radium when processing the uranium ore. In laboratory tests conducted by the Federal Bureau of Mines, radium was leached from tailings using either hydrochloric acid or ethylenediamine tetraacetic acid. A hydrochloric acid leaching method was used to extract both radium and uranium from the ore to yield tailings containing less radium than those produced by either conventional sulfuric acid or alkaline leaching processes. From 77 to 94 percent of the radium in mill tailings was concentrated by sedimentation in slime fractions representing nearly 25 weight-percent of the original sample.

Jan 1, 1975

By Henry M. Harris, John E. Kelley, Thomas D. Roberts

A penetrometer apparatus for measuring viscosity of glass at temperatures up to 1,450 ° C was developed for use in establishing the viscosity coefficients required for high- temperature forming of ceramic materials . The major advantage of the method is that it can be used with samples of almost any shape or size without the necessity of forming or measuring shapes to close dimensional tolerances . Also , it has proved accurate in the range of 106 to 109 poises , a gap between the normal limits of other methods . The device , which operates on a single penetrometer principle , was used to determine the absolute viscosity coefficient of substances in centimeter - gram- second units of poises instead of relative penetration - rate units as with other penetrometers . Penetration of the viscous sample was sensed with a linear , variable differential transformer . The output of this transformer was recorded versus time , and the penetration rate was used in calculating the viscosity coefficient . The general equation relating penetration rate and viscosity coefficient was found to be 11 = F ( ln L/a 0.72 ) 2 π UL · where is the viscosity coefficient in poises , F is the penetrator load in dynes , L is the penetration depth in centimeters, a is the penetrator radius in centimeters and U is the penetration rate in centimeters per second . The penetrometer was tested using a standard viscosity sample of sodalime - silica glass obtained from the National Bureau of Standards ( NBS ) . Values obtained at several temperatures all agreed within 10 percent with comparable data calculated from the Fulcher equation derived by NBS for this glass . Equivalent accuracy was obtained with other glasses used to evaluate the apparatus .

Jan 1, 1964

By I. S. Solet

This study, of the liquidus temperatures and densities of molten alloys of zinc and aluminum was made as part of a broader investigation on refining of scrap aluminum. One of the methods of refining involves the separation of liquid and solid phases by gravity segregation and by filtration. More accurate data were required on the liquidus temperatures and the densities of molten&apos; mixtures of the metals than were available in the technical literature. New data on the liquidus curve were obtained by thermal analysis. The new temperatures are, for the most part) somewhat higher than those reported previously by other investigators. The density of molten mixtures of zinc and aluminum were found to be less than would be calculated by assuming that the two metals occupy the same respective molal volumes in solution as they do as pure metals.

Jan 1, 1949